News Briefs

Is it finally the end of fad diet wars?
It’s not the type of diet that makes a difference it’s cutting back on the calories that counts. This is the principal finding of a study in the prestigious New England Journal of Medicine that compared four heart-healthy, weight-loss diets. Consisting of similar foods, the diets replaced saturated with unsaturated fat and were high in whole cereal grains, fruits and vegetables. All participants were encouraged to include at least 20 g of dietary fibre per day in their diet and low GI carb-rich foods were recommended.

All four diets were equally successful in promoting clinically meaningful weight loss and the maintenance of weight loss over the course of 2 years. The take-home message is that giving people who want to lose weight a reduced calorie diet that's specifically tailored to fit in with their personal and cultural food preferences is likely to be the best way to give them a real chance for long-term success.

The researchers randomly assigned 811 overweight adults who were very keen to lose weight to one of four diets with a 750 calorie reduction a day that emphasised different amounts of carbohydrates, fat, and protein. The participants were also asked to do 90 minutes of moderate exercise a week. ‘Among the 80% of participants who completed the trial, the average weight loss was 4 kg (8.8 lbs); 14 to 15% of the participants had a reduction of at least 10% of their initial body weight.’ All the diets reduced risk factors for cardiovascular disease and diabetes.

Prof Frank Sacks

The study also showed that the participants who regularly attended counselling sessions lost more weight than those who didn’t. Lead author Prof. Frank Sacks said: ‘These findings suggest that continued contact with the participants may be more important than the micronutrient composition of their diets.’

The good news: If you want to lose weight, see a registered dietitian.
The bad news: It's unlikely that such science-based evidence from Harvard researchers will stop the flow of fad diet books, magazine stories or miracle weight-loss programs, pills and potions.

Helping kids beat the obesity gene
‘Although our genetic make-up does have an influence on our health, it’s certainly not the only defining factor. Those with high risk genes can, in some cases, resist their genetic lot if they alter their lifestyle in the right way – in this case, their diet,’ says lead author Dr Laura Johnson from University College London (UCL) talking about a new study published in March 2009 issue of the online journal PloS One.

Dr Laura Johnson

Children who carry the FTO gene, strongly associated with obesity, could offset its effect by eating a low energy density diet. The UCL and University of Bristol researchers found that children with a more energy dense diet (more calories per bite) tended to have more fat mass three years later and also confirmed that those carrying the high risk gene had greater fat mass overall.

When the researchers looked at whether children with the FTO gene had a stronger reaction to an energy dense diet than children with a lower genetic risk they found that they did not. These results indicate that if a child with a high genetic risk eats a diet with fewer calories per bite, they may be able to offset the effect of the gene on weight gain and so stay a healthy weight.

Eating a diet rich in energy-dense foods increases the risk of obesity for adults, as they tend to eat the same amount of food, regardless of its energy density. That’s not true for kids, Johnson notes. When younger kids eat energy-dense foods, they generally eat less at the next meal. As they get older, though, they get more and more like adults. ‘This is an important finding because it provides evidence that … adopting a diet with more bulk and less energy per bite could help people avoid becoming obese regardless of their genetic risk. Obesity is not inevitable if your genes give you a higher risk because if you change the types of foods you eat this will help curb excessive weight gain.’

How? By replacing high-fat foods with low-fat foods and giving kids more fruits and vegetables. See January 2009 GI News for more on low energy density ‘feel full’ foods and February 2009 GI News for tips on ‘Changing the way we eat, drink and move.’

Carbohydrate withdrawal: is recognition the first step to recovery?
In February 2009 GI News, we reported on an article that explored the idea in that addiction could be an important factor causing the obesity epidemic. Lead writer Dr Simon Thornley claimed that although there’s no basis for this in the medical literature to date, it’s possible that obese persons may experience a withdrawal syndrome (after abstinence from high GI foods) with symptoms such as craving and low mood similar to those associated with other drug dependencies. In a recent letter to the NZ Medical Journal, Thornley reprints correspondence (with permission) from a 38-year-old woman from Wisconsin, USA.


“For the first 3 weeks I cut all processed sugar and flour from my diet and suffered mood swings with extreme tension and depression, even a sense of hopelessness at times, I had horrible stomach pains, all my joints and muscles throbbed, and I had the shakes constantly. I don't even know how to describe the horrible headaches that went along with all this. People who knew me started thinking I was hiding a drug problem. The worst physical symptoms have been gone for about 2 weeks now, and the cravings are finally starting to subside … I look at birthday cake today and all I see is myself curled up in the fetal position crying in bed … The worst part of the addiction lasted 3 weeks. The first 3 days were normal, but then on the fourth day the worst cravings began. All I could think about was ice cream, chocolate, and cheesecake. The cravings started to subside after the third week, but once I started feeling better I [thought] about food less. The shakes and the headaches really were the worst part!”

Thornley says: ‘Although this case does not prove our hypothesis, it may explain why obese people find it difficult to adhere to advice to reduce intake of refined carbohydrates. Her description is similar to an opiate withdrawal syndrome (craving, aches and pains and muscular spasm or twitching). The time course – worst in the first weeks and resolving with continued abstinence within 4 weeks – again concurs with a withdrawal syndrome. Further work may indicate if these symptoms can be reliably measured and mapped over time in obese subjects that limit their intake of high GI food.’